With the development of display manufacturing technology, TFT-LCD (Thin Film Transistor Liquid Crystal Display, a thin film transistor liquid crystal display) plays a leading role in the current flat panel display market owing to its advantages such as small size, low consumption, no radiation and the like. An array substrate is an important component of a liquid crystal display device. Aperture ratio is an important index evaluating an array substrate. The greater the aperture ratio is, the higher the light transmittance of the array substrate will be, and therefore the higher the brightness of TFT-LCD using the array substrate will be and the better the display effect of the liquid crystal display will be.
Existing array substrates typically encounter the problem of light leakage, which is generally solved by broadening a black matrix. Aperture ratio is equal to the ratio of the area of the light-transmitting portion in a pixel to the total area of the pixel. However, a black matrix is not light-transmitting and broadening thereof will reduce the area of the light-transmitting portion in the pixel. Therefore, by broadening a black matrix to solve light leakage of an array substrate in the prior art, the aperture ratio of TFT would be reduced, thereby reducing the transmittance of the array substrate.